Aldehyde synthesis



United States Patent G M 3,369,048 ALDEHYDE SYNTHESIS Lyle .A. Hamilton,Pitrnan, and Phillip S. Lantlis, Woodbury, N.J., assignors to Mobil OilCorporation, a corporation of New York No Drawing. Filed Aug. 8, 1963,Ser. No. 300,904 12 Claims. (Cl. 260599) This application is directed tothe preparation of aldehydes and, more particularly, to the use ofcrystalline aluminosilicate catalysts in the preparation of aldehydes.

The preparation of aromatic aldehydes by the direct introduction of aformyl group through the use of carbon monoxide, hydrogen chloride and asuitable catalyst is well known as the Gattermann-Koch reaction. Thissynthesis is a special type of Friedel-Crafts reaction and isexemplified through the formation of p-tolualdehyde from toluene, asfollows:

00, E01 CH Hal) gg H3O The Gatte rmann-Koch reaction is normally carriedout by passing a mixture of gaseous carbon monoxide and hydrogenchloride into a suspension of cuprous chloride and aluminum chloride inthe liquid of the reactant starting material. In general, it provides aconvenient mechanism for the production of aromatic aldehydes and, infact, is particularly useful for the single step production ofbenzaldehyde and the monoalkyl and polyalkyl benzaldehydes.

In accordance with the present invention, it has now been discoveredthat the Gattermann-Koch reaction and similar reactions may now becarried out extremely satisfactorily and economically by means of aunique class of catalytic materials other than the conventionallyemployed aluminum chloride and like catalysts, namely crystallinealuminosilicates. Such catalysts are not only effective for carrying outa Gattermann-Koch type synthesis with high reaction rates and excellentyield but increase the commercial feasibility of the reaction since suchcrystalline aluminosilicates have extremely long life and may be readilyregenerated for re-use. Aluminum chloride, on the other hand, cannot beregenerated readily.

It is accordingly a primary object of the present invention to provide anovel technique for conducting a Gattermann-Koch type synthesis.

It is a further object of the present invention to provide a novelmethod of carrying out a Gattermann-Koch type synthesis by means ofsolid porous crystalline aluminosilicate catalysts.

It is still another important object of the present invention to providea novel methodof conducting a Gattermann-Koch type synthesis underparticularly practicable reaction conditions through the utilization ofthe acid form of solid porous crystalline aluminosilicate catalysts.

It is a further important object of the present invention to provide anovel process of conducting a Gattermann- Koch type synthesis throughthe use of solid porous crystalline aluminosilicate catalysts containingmetal cations which serve as promoters for the reaction.

These and further important advantages and objects of the presentinvention will become more apparent upon reference to the ensuingdescription and appended claims.

Certain zeolitic materials, both natural and synthetic, in naturallyoccurring and modified forms, have been demonstrated in the past to havecatalytic capabilities for various types of hydrocarbon conversion andother reactions involving the synthesis or modification of variousorganic materials. Such zeolitic materials are ordered crystallinealuminosilicates having a definite crystalline struc- Patented Feb. 13,1968 ture within which there are passages, pores or cavities of definiteranges of size. Since the dimensions of these pores are such as toaccept for adsorption molecules of certain dimensions while rejectingthose of larger dimensions, these materials have come to be known asmolecular sieves and are utilized in a variety of ways to take advantageof these properties.

The present invention, as aforesaid, involves the use of such zeoliticmaterials for the purposes of carrying out a Gattermann-Koch typesynthesis to form aldehydes under conditions which are extremelysatisfactory for practicable commercial operations and with surprisinglysuperior results.

In general, the synthesis of the present invention may be described bythe following equation:

0 O H C l Crystalline aluminosilicate In the above equation, thepreferred value of R is an aromatic radical. A description of theGattermann-Koch type synthesis is set forth in Organic Reactions, vol.V, pp. 290-300, edited by R. Adams et al., John Wiley & Sons, New York(1949), and in Anhydrous Aluminum Chloride in Organic Chemistry, by C.A. Thomas, chapt. 10, pp. 595600, which descriptions are herebyincorporated by reference. The former reference enumerates a variety ofstarting materials which may be considered representative of materialsuseable in the process of the present invention. Aside from theforegoing, the starting materials useable herein quite obviously may beany of those normally operable to form aldehydes in accordance with thewell known Gattermann-Koch type of reaction.

The aluminosilicates useable as catalysts in accordance with the presentinvention include a wide variety of positive ion-containing crystallinealuminosilicates, both natural and synthetic. Thesse aluminosilicatescan be described as a rigid three-dimensional network of $0., and A10tetrahedra in which the tetrahedra are cross-linked by the sharing ofoxygen atoms whereby the ratio of the total aluminum and silicon atomsto oxygen atoms is 1:2. The electrovalence of the tetrahedra containingaluminum is balanced by the inclusion in the crystal of a cation, forexample, a hydrogen, ammonium, alkali metal or alkaline earth metalcation. This equilibrium can be expressed by formula wherein the ratioof A1 to the number of the various cations, such as Ca, Sr, Na K or Liis equal to unity. One cation may be exchanged either in entirety orpartially by another cation utilizing ion exchange techniques asdiscussed hcreinbelow. By meanss of such cation exchange, it is possibleto vary the size of the pores in the given aluminosilicate by suitableselection of the particular cation. The spaces between the tetrahedraare occupied by molecules of water prior to dehydration.

A description of zeolites of the type useable in the present inventionis found in Patent 2,971,824, Whose disclosure is hereby incorporatedherein by reference. These aluminosilicates have well-definedintra-crystalline dimensions such that only reactant or productmolecules of suitable size and shape may be transported in eitherdirection between the exterior phase and the interior of the crystallinezeolite.

In their hydrated form, the aluminosilicates may be represented by theformula:

wherein M is a carbon which balances the electrovalence of thetetrahedra, n represents the valence of the cation, w the moles of SiOand y the moles of H 0, the removal of which produces the characteristicopen network system. The cation may be any one or more of a number ofpositive ions as aforesaid, such ions being discussed in greater detailhereinafter. The parent zeolite is dehydrated RoHo 1.0:0.2M O:Al O:2.5i0.5SiO :yH O (II) wherein M is a metal cation having a valence ofnot more than three, n represents the valence of M, and y is a value upto eight depending on the identity of M and degree of hydration of thecrystal. The sodium form may be represented in terms of mole ratios ofoxides as follows:

Another synthesized crystalline aluminosilicate, designated Zeolite A,can be represented in mole ratios of oxides as:

wherein M represents a metal cation, n is the valence of M, and y is anyvalue up to about 6. As usually prepared, Zeolite A contains primarilysodium cations and is designated sodium Zeolite A.

Other suitable synthesized crystalline aluminosilicates are thosedesignated Zeolite Y, L, D and T.

The formula for Zeolite Y (which is a synthetic faujasite) expressed inoxide mole ratios is:

0.9 i 0.2N3z01A1203I1'1S1021YH20 wherein w is a value ranging from 3 .to6 y may be any value up to about 9.

The composition of Zeolite L in oxide mole ratios may be represented as:

1.0:0.1M ,,O:Al O :6.4i0.5SiO :yH O (VI) wherein M designates a metalcation, n represents the valence of M, and y is any value from to 7.

The formula for Zeolite D, in terms of oxide mole ratios, may berepresented as:

0.9:0.2[xNa O: (1x)K O] :A1 O :wSiO :yH O (VII) wherein x is a value of0 to 1, w is from 4.5 to about 4.9 and y, in the fully hydrated form, isabout 7.

The formula for Zeolite T in terms of oxide mole ratios may be Writtenas:

1.1i0.4xNa O: (1x)-K O:

Al O :6.9i0.5SiO :yH 0 (VIII) wherein x is any value from about 0.1 toabout 0.8 and y is any value from about 0 to about 8.

Other synthesized crystalline aluminosilicates include those designatedas ZK-4 and ZK-S.

ZK-4 can be represented in terms of mole ratios of oxides as:

0.1 to 0.3R:0.7 to 1.0M2/n0 :Al O :2.5 to 4.0SiO :yH O (IX) wherein R isa member selected from the group consisting of methylammonium oxide,hydrogen oxide and mixtures thereof with one another, M is a metalcation, n is the valence of the cation, and y is any value from about3.5 to about 5.5. As usually synthesized, Zeolite ZK-4 contiansprimarily sodium cations and can be represented by unit cell formula:

The major lines of the X-ray diffraction pattern of ZK-4 are set forthin Table 1 below:

Table I d Value of reflection in A.: [/1

ZK-4 can be prepared by preparing an aqueous solution of oxidescontaining Na O, A1 0 SiO H 0 and tetramethyl-amrnonium ion having acomposition, in terms of oxide mole ratios, which falls within thefollowing ranges:

SiO /A1 0 2.5 to 11 Na20/Na20-i-[(CH3)4N]2O 05 to 1 to 2 H O/Na O+[(CHN] O 25 to 50 maintaining the mixture at a temperature of about 100 C.to C. until the crystals are formed, and separating the crystals fromthe mother liquor. The crystal material is thereafter washed until thewash efiluent has a pH essentially that of wash Water and subsequentlydried.

ZK*5 is representative of another crystalline aluminosilicate which isprepared in the same manner as Zeolite ZK-4 except thatN,N'-dimethyltriethylenediammonium hydroxide is used in place oftetramethylammonium hydroxide. ZK-S may be prepared from an aqueoussodium aluminosilicate mixture having the following compositionexpressed in terms of oxide mole ratios as:

SiO /Al O 2.5 to Na O/Na O+[(CH N (CH ]OH t0 H O/Na O+[(CH N (CH ]OH 25to 50 The N,N'-dimethyltriethylenediammonium hydroxide used in preparingZK-S can be prepared by methylating 1,4-diazabicyclo-(2.2.2)-octane withmethyl iodide or dimethyl sulfate, followed by conversion to thehydroxide by treatment with silver oxide or barium hydroxide. Thereaction may be illustrated as follows:

hydroxide compound in the preparation of ZK-S, the hydroxide may beemployed per se, or further treated with a source of silica, such assilica gel, and thereafter reacted with aqueous sodium aluminate in areaction mixture whose chemical composition corresponds to theabove-noted oxide mole ratios. Upon heating at temperatures of about 200to 600 C., the methyl ammonium ion is converted to hydrogen ion.

Quite obviously, the above-listed molecular sieves are onlyrepresentative of the synthetic crystalline aluminosilicate molecularsieve catalysts which may be used in accordance with the process of thepresent invention, the particular enumeration of such sieves not beingintended to 'be exclusive.

At the present time, three commercially available moleoular sieves arethose of the A series and of the X series and a synthetic mordenite. Asynthetic zeolite known as Molecular Sieve 4A is a crystalline sodiumaluminosilicate having an effective pore diameter of about 4 Angstroms.In the hydrated form, this material is chemically characterized by theformula:

12 2) 12 z) 12 27H2O The synthetic zeolite known as Molecular Sieve 5Ais a crystalline aluminosilicate salt having anetfective pore diameterof about 5 Angstroms and in which substantially all of the 12 ions ofsodium in the immediately above formula are replaced by calcium, itbeing understood that calcium replaces sodium in the ratio of onecalcium ion for two sodium ions. A crystalline sodium aluminosilicate isalso available commercially under the name of Molecular Sieve 13X. Theletter X is used to distinguish the inter-atomic structure of thiszeolite from that of the A crystal mentioned above. As initiallyprepared and before activation by dehydration, the 13X materialcontainswater and has the unit cell formula Chabazite (Na O-Al O -4SiO -6H O)Gmelinite (N320 A1203 Mordenite (Na o 'Al O IOSiO 6.6H O) Mordenite,found in nature as the mixed sodium-calcium salt, appears to be a densealuminosilicateincapable of sorbing normal butane, for example. Iffinely crushed and contacted with aqueous mineral acids to base-exchangethe sodium, however, the resulting crystalline alu- 6 minosilicatebecomes a good sorbent for benzene, toluene, etc., and an effectivecatalyst in the present invention. Other aluminosilicates which can beused are those resulting from caustic treatment of various clays.

Of the clay materials, montmorillonite and kaolin families arerepresentative types which include the subbentonites, such as bentonite,and the kaolins commonly identified as Dixie, McNamee, Georgia andFlorida clays in which the main mineral constituent is halloysite,kaolinite, dickite, nacrite or anauxite. Such clays may be used in theraw state as originally mined or initially subjected to calcination,acid treatment or chemical modification. In order to render the clayssuitable for use, however, the clay material is treated with sodiumhydroxide or potassium hydroxide, preferably in admixture with a sourceof silica, such as sand, silica gel or sodium silicate, and calcined attemperatures ranging from 230 F. to 1600 F. Following calcination, thefused material is crushed, dispersed in water and digested in theresulting alkaline solution. During the digestion, materials withvarying degrees of crystallinity are crystallized out of solution. Thesolid material is separated from the alkaline material and thereafterwashed and dried. The treatment can be effected by reacting mixturesfalling Within the following weight ratios: 1

Na O/clay (dry basis) 1.0-6.6 to 1 SiO /clay (-dry basis) 0.013.7 to 1 HO/Na O (mole ratio) 35-180 to 1 Molecular sieves are ordinarily preparedinitially in the sodium form of the crystal. The sodium ions in suchform may, as desired, be exchanged for other cations, as will bedescribed in greater detail below. In general, the process ofpreparation involves heating, in aqueous solution, an appropriatemixture of oxides, or of materials whose chemical composition can becompletely represented as a mixture ofoxides Na O, A1 0 SiO and H 0 at atemperature of approximately 100 C..for pe riods of 15 minutes to hoursor more. The product which crystallizes Within this hot mixture isseparated therefrom and water washed until the water in equilibrium withthe zeolite has a pH in the range of 9 to 12. After activating byheating until dehydration is attained, the substance is ready for use.

For example, in the preparation of sodium zeolite A, suitable reagentsfor the source of silica include silica sol, silica gel, silicic acid orsodium silicate. Alumina can be supplied by utilizing activatingalumina, gamma alumina, alpha alumina, aluminum trihydrate or sodiumaluminate. Sodium hydroxide is suitably used as the source of the sodiumion and in addition contributes to the regulation of the pH. Allreagents are preferably soluble in water. The reaction solution has acomposition, expressed as mixtures of oxides, within the followingranges: SiO /Al O of 0.5 to 2.5, Na O/SiO of 0.8 to 3.0 and H O/Na O of35 to 200. A convenient and generally employed process of preparationinvolves preparing an aqueous solution of sodium aluminate and sodiumhydroxide and then adding with stirring an aqueous solution of sodiumsilicate.

The reaction mixture is placed in a suitable vessel which is closed tothe atmosphere in order to avoid losses of water and the reagents arethen heated for an appropriate length of time. Adequate time must beused to allow for recrystallization of the first amorphous precipitatethat forms. While satisfactory crystallization may be obtained attemperatures from 21 C. to 150 C., the pressure being atmospheric orless, corresponding to the equilibrium of the vapor pressure with themixture at the reaction temperature, crystallization is ordinarilycarried out at about C. As soon as the zeolite crystals are completelyformed they retain their structure and it is not essential to maintainthe temperature of the reaction any longer in order to obtain a maximumyield of crystals.

After formation, the crystalline zeolite is separated from the motherliquor, usually by filtration. The crystalline mass is then washed,preferably with salt-free water, while on the filter, until the washWater, in equilibrium with the zeolite, reaches a pH of 9 to 12. Thecrystals are then dried at a temperature between 25 C. and 150 C.Activation is attained upon dehydration, as for example at 350 C. and 1mm. pressure or at 350 C. in a stream of dry air.

It is to be noted that the material first formed on mix ing thereactants is an amorphous precipitate which is, generally speaking, notcatalytically active in the process of the invention. It is only aftertransformation of the amorphous precipitate to crystalline form that thehighly active catalyst described herein is obtained.

Molecular sieves of the other series may be prepared in a similarmanner, the composition of the reaction mixture being varied to obtainthe desired ratios of ingredients for the particular sieve in question.

The molecular sieve catalysts useable in the process of the presentinvention may be in the sodium form as aforesaid or many contain othercations, including other metallic cations and/or hydrogen. In preparingthe nonsodium forms of the catalyst composition, the aluminosilicate canbe contacted with a non-aqueous or aqueous fluid medium comprising agas, polar solvent or water solution containing the desired positiveion. Where the aluminosilicate is to contain metal cations, the metalcations may be introduced by means of a salt soluble in the fluidmedium. When the aluminosilicate is to contain hydrogen ions, suchhydrogen ions may be introduced by means of a hydrogen ion-containingfluid medium or a fluid medium containing ammonium ions capable ofconversion to hydrogen ions.

In those cases in which the aluminosilicate is to contain both metalcations and hydrogen ions, the aluminosilicate may be treated with afluid medium containing both the metal salt and hydrogen ions orammonium ions capable of conversion to hydrogen ions. Alternatively, thealuminosilicate can be first contacted with a fluid medium containing ahydrogen ion or ammonium ion capable of conversion to a hydrogen ion andthen with a fluid medium containing at least one metallic salt.Similarly, the aluminosilicate can be first contacted with a fluidmedium containing at least one metallic salt and then with a fluidmedium containing a hydrogen ion or an ion capable of conversion to ahydrogen ion or a mixture of both.

Water is the preferred medium for reasons of economy and ease ofpreparation in large scale operations involving continuous or batchwisetreatment. Similarly, for this reason, organic solvents are lesspreferred but can be employed providing the solvent permits ionizationof the acid, ammonium compound and metallic salt. Typical solventsinclude cyclic and acyclic ethers such as dioxane, tetrahydro-furan,ethyl ether, diethyl ether, diisopropyl ether, and the like; ketonessuch as acetone and methyl ethyl ketone; esters such as ethyl acetate,propyl acetate; alcohols such as ethanol, propanol, butanol, etc.; andmiscellaneous solvents such as dimethylformamide, and the like.

The hydrogen ion, metal cation or ammonium ion may be present in thefluid medium in an amount varying within wide limits dependent upon thepH value of the fluid medium. Where the aluminosilicate material has amolar ratio of silica to alumina greater than about 5.0, the fluidmedium may contain a hydrogen ion, metal cation, ammonium ion, or amixture thereof, equivalent to a pH value ranging from less than 1.0 upto a pH value of about 10.0. Within these limits, pH values for fluidmedia containing a metallic cation and/or an ammonium ion range from 4.0to 10.0, and are preferably between a pH value of 4.5 to 8.5. For fluidmedia containing a hydrogen ion alone or with a metallic cation.

the pH values range from less than 1.0 up to about 7.0 and arepreferably within the range of less than 3.0 up to 6.0. Where the molarratio of the aluminosilicate is greater than about 3.0 and less thanabout 5.0, the pH value for the fluid media containing a hydrogen ion ora metal cation ranges from 3.8 to 8.5. Where ammonium ions are employed,either alone or in combination with metallic cations, the pH valueranges from 4.5 to 9.5 and is preferably within the limit of 4.5 to 8.5.When the aluminosilicate material has a molar ratio of silica to aluminaless than about 3.0, the preferred medium is a fluid medium containingan ammonium ion instead of a hydrogen ion. Thus, depending upon thesilica to alumina ratio, the pH value varies within rather wide limits.

In carrying out the treatment with the fluid medium, the procedureemployed comprises contacting the aluminosilicate with the desired fluidmedium or media until such time as metallic cations originally presentin the aluminosilicate are removed to the desired extent. Repeated useof fresh solutions of the entering ion is of value to secure morecomplete exchange. Eifective treatment with the fluid medium to obtain amodified aluminosilicate having high catalytic activity will vary, ofcourse, with the duration of the treatment and temperature at which itis carried out. Elevated temperatures tend to hasten the speed oftreatment whereas the duration thereof varies inversely with theconcentration of the ions in the fluid medium. In general, thetemperatures employed range from below ambient room temperature of 24 C.up to temperatures below the decomposition temperature of thealuminosilicate. Following the fluid treatment, the treatedaluminosilicate is washed with water, preferably distilled water, untilthe effluent wash water has a pH value of wash water, i.e., betweenabout 5 and 8. The aluminosilicate material is thereafter analyzed formetallic ion content by methods well known in the art. Analysis alsoinvolves analyzing the efiiuent wash for anions obtained in the wash asa result of the treatment, as well as determination of and correctionfor anions that pass into the efliuent wash from soluble substances ordecomposition products of insoluble substances which are otherwisepresent in the aluminosilicate as impurities. The aluminosilicate isthen dried and dehydrated.

The actual procedure employed for carrying out the fluid treatment ofthe aluminosilicate may be accomplished in a batchwise or continuousmethod under atmospheric, subatmospheric or superatmospheric pressure. Asolution of the ions of positive valence in the form of a moltenmaterial, vapor, aqueous or non-aqueous solution, may be passed slowlythrough a fixed bed of the aluminosilicate. If desired, hydrothermaltreatment or a corresponding non-aqueous treatment with polar solventsmay be effected by introducing the aluminosilicate and fluid medium intoa closed vessel maintained under autogenous pressure. Similarly,treatments involving fusion or vapor phase contact may be employedproviding the melting point or vaporization temperature of the acid orammonium compound is below the decomposition temperature of thealuminosilicate.

A Wide variety of acidic compounds can be employed with facility as asource of hydrogen ions and include both inorganic and organic acids.

Representative inorganic acids which can be employed include acids suchas hydrochloric acid, hypochlorous acid, chloroplatinic acid, sulfuricacid, sulfurous acid, hydrosulfuric acid, peroxydisulfonic acid (H S Operoxymonosulfuric acid (H 50 dithionie acid (H S O sulfamic acid (H NHSH), amidosulfonic acid chlorosulfuric acid, thiocyanic acid,hyposulfurous acid (H S O pyrosulfuric acid (H S O thiosulfuric acid (P18 0 nitrosulfonic acid (HSO .NO), hydroxylamine disulfonic acid [(HSONOH], nitric acid, nitrous acid, hyponitrous acid, carbonic acid and thelike.

Typical organic acids which find utility in the practice of theinvention include the monocarboxylic, dicarboxylic and polycarboxylicacids which can be aliphatic, aromatic or cycloaliphatic in nature.

Representative aliphatic monocarboxylic, dicarboxylic and polycarboxylicacids include the saturated and unsaturated, substituted andunsubstituted acids such as formic acid, acetic acid, chloroacetic acid,dichloroacetic acid, trichloroacetic acid, bromoacetic acid, propionicacid, 2-bromopropionic acid, 3-bromopropionic acid, lactic acid,n-butyric acid, isobutyric acid, crotonic acid, n-valeric acid,isovaleric acid, n-caproic acid, oenanthic acid, pelargonic acid, capricacid, undecyclic acid, lauric acid, myristic acid, palmitic acid,stearic acid, oxalic acid, malonic acid, succinic acid, glutaric acid,adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,alkylsuccinic acid, alkenylsuccinic acid, maleic acid, fumaric acid,itaconic acid, citraconic acid, mesaconic acid, glutonic acid, muconicacid, ethylidene malonic acid, isopropylidene malonic acid, allylmalonic acid.

Representative aromatic and cycloaliphatic monocarboxylic, dicarboxylicand polycarboxylic acids include 1,2-cyclohexanedicarboxylic acid,1,4-cyclohexanedicarboxylic acid, 2-carboxy-2-methylcyclohexaneaceticacid, phthalic acid, isophthalic acid, terephthalic acid,1,8-naphthalenedicarboxylic acid, 1,2-naphthalenedicarboxylic acid,tetrahydrophthalic acid, 3-carboxy-cinnamic acid, hydrocinnamic acid,pyrogallic acid, benzoic acid, ortho, meta and para-methyl, hydroxy,chloro, bromo and nitrosubstituted benzoic acids, phenylacetic acid,mandelic acid, benzylic acid, hippuric acid, benzenesulfonic acid,toluenesulfonic acid, methanesulfonic acid and the like.

Other sources of hydrogen ions include carboxy polyesters prepared bythe reaction of an excess of polycarboxylic acid or an anhydride thereofand a polyhydric alcohol to provide pendant carboxyl groups.

Still other materials capable of providing hydrogen ions are ionexchange resins having exchangeable hydrogen ions attached to baseresins comprising cross-linked resinous polymers of monovinyl aromaticmonomers and polyvinyl compounds. These resins are well known materialswhich are generally prepared by copolymerizing in the presence of apolymerization catalyst one or more monovinyl aromatic compounds, suchas styrene, vinyl toluene, vinyl xylene, with one or more divinylaromatic compounds such as divinyl benzene, divinyl toluene divinylxylene, divinyl naphthalene and divinyl acetylene. Following thecopolymerization, the resins are sulfonated to provide the hydrogen formof the resin.

Still another class of compounds which can be employed are ammoniumcompounds which decompose to provide hydrogen ions when analuminosilicate treated with a solution of said ammonium compound issubjected to temperatures below the decomposition temperature of thealuminosilicate.

Representative ammonium compounds which can be employed include ammoniumchloride, ammonium bromide, ammonium iodide, ammonium carbonate,ammonium sulfate, ammonium sulfide, ammonium thiocyanate, ammoniumdithiocarbamate, ammonium peroxysulfate, ammonium acetate, ammoniumtungstate, ammonium molybdate, ammonium benzoate, ammonium borate,ammonium carbamate, ammonium sesquicarbonate, ammonium chloroplumbate,ammonium citrate, ammonium dithionate, ammonium fluoride, ammoniumgallate, ammonium nitrate, ammonium nitrite, ammonium formate, ammoniumpropionate, ammonium butyrate, ammonium valerate, ammonium lactate,ammonium malonate, ammonium oxalate, ammonium palmitate, ammoniumtartrate and the like. Still other ammonium compounds which can beemployed include complex ammonium compounds such as tetramethylammoniumhydroxide, trimethylammonium chloride. Other compounds which can beemployed are nitrogen bases such as the salts of guanidine, pyridine,quinoline, etc. I

A wide variety of metallic compounds can be employed with facility as asource of metallic cations and include both inorganic and organic saltsof the metals of Groups I through VIII of the Periodic Table.

Representative of the salts which can be employed include chlorides,bromides, iodides, carbonates, bicarbonates, sulfates, sulfides,thiocyanates, dithiocarbamates, peroxysulfates, acetates, benzoates,citrates, fluorides, nitrates, nitrites, formates, propionates,butyrates, valerates, lactates, malonates, oxalates, palmitates,hydroxides, tartrates and the like. The only limitation on theparticular metal salt employed is that it be soluble in the fluid mediumin which it is used. The preferred salts are the chlorides, nit-rates,acetates and sulfates.

Rare earth salts may be advantageously employed. Such salts can eitherbe the salt of a single metal or, preferably, of mixtures of metals suchas a rare earth chloride or didymium chlorides. As hereinafter referedto, a rare earth chloride solution is a mixture of rare earth chloridesconsisting essentially of the chlorides of lanthanum, cerium, neodymiumand praseodymium with minor amounts of samarium, gadolinium and yttrium.The rare earth chloride solution is commercially available and itcontains the chlorides of a rare earth mixture having the relativecomposition: cerium (as CeO 48% by weight; lanthanum (as La O 24% byweight; praseodymium (as Pr O 5% by Weight; neodymium (as Nd O 17% byweight; samarium (as Sm O 3% by weight; gadolinium (as Gd O 2% byweight; yttrium (as Y O 0.2% by weight; and other rare earth oxides 0.8%by weight. Dydymium chloride is also a mixture of rare earth chlorides,but having a 10W cerium content. It consists of the following rareearths determined as oxides: lanthanum, 45-46% by weight; cerium, 12% byweight; praseodymium, 910% by weight; neodymium, 32-33% by weight;samarium, 5-6% by weight; gadolinium, 34% by weight; yttrium, 0.4% byweight; other rare earths, 12% by weight. It is to be understood thatother mixtures of rare earths are equally applicable in the instantinvention.

Representative metal salts which can be employed, aside from the mixturementioned above, include silver sulfate, silver nitrate, silver acetate,silver arsinate, silver citrate, silver carbonate, silver oxide, silvertartrate, calcium acetate, calcium arsenate, calcium benzoate, calciumbromide, calcium carbonate, calcium chloride, calcium citrate, berylliumbromide, beryllium carbonate, beryllium hydroxide, beryllium sulfate,barium acetate, barium bromide, barium carbonate, barium citrate, bariummalonate, barium nitrite, barium oxide, barium sulfide, cuprouschloride, cuprous acetate, cuprous sulfate, magnesium chloride,magnesium bromide, magnesium sulfate, magnesium sulfide, magnesiumacetate, magnesiurn formate, magnesium stearate, magnesium tartrate,manganese chloride,, manganese sulfate, manganese acetate, manganesecarbonate, manganese formate, zinc sulfate, zinc nitrate, zinc acetate,zinc chloride, zinc bromide, aluminum chloride, aluminum bromide,aluminum acetate, aluminum citrate, aluminum nitrate, aluminum oxide,aluminum phosphate, aluminum sulfate, titanium bromide, titaniumchloride, titanium nitrate, titanium sulfate, zirconium chloride,zirconium nitrate, zirconium sulfate, chromic acetate, chromic chloride,chromic nitrate, chromic sulfate, ferric chloride, ferric bromide,ferric acetate, ferrous chloride, ferrous arsenate, ferrous lactate,ferrous sulfate, nickel chloride, nickel bromide, cerous acetate, cerousbromide, cerous carbonate, cerous chloride, cerous iodide, ceroussulfate, cerous sulfide, lanthanum chloride, lanthanum bromide,lanthanum nitrate, lanthanum sulfate, lanthanum sulfide, yttriumbromate, yttrium bromide, yttrium chloride, yttrium nitrate, yttriumsulfate, samarium acetate, samarium chloride, samarium bromide, samariumsulfate, neodymium chloride, neodymium oxide, neodymium sulfide,neodymium sulfate, praseodymium chloride, praseodymium bromide,praseodymium sulfate, praseodymium sulfide, selenium 1 1 chloride,selenium bromide, tellurium chloride, tellurium bromide, etc.

The aluminosilicate catalysts useable in connection with the process ofthe present invention may be used in powdered, granular or molded stateformed into spheres or pellets of finely divided particles having aparticle size of 2 to 500 mesh. In cases where the catalyst is molded,such as by extrusion, the aluminosilicate may be extruded before drying,or dried or partially dried and then extruded. The catalyst product isthen preferably precalcined in an inert atmosphere near the temperaturecontemplated for conversion but may be calcined initially during use inthe conversion process. Generally, the aluminosilicate is dried between150 F. and 600 F. and thereafter calcined in air or an inert atmosphereof nitrogen, hydrogen, helium, flue gas or other inert gas attemperatures ranging from about 500 F. to 1500 F. for periods of timeranging from 1 to 48 hours or more.

The aluminosilicate catalysts prepared in the foregoing manner may :beused as catalysts per se or as intermediates in the preparation offurther modified contact masses consisting of inert and/or catalyticallyactive materials which otherwise serve as a base, support, carrier,binder, matrix or promoter for the alminosilicate. One embodiment of theinvention is the use of finely divided aluminosilicate catalystparticles in a siliceous gel matrix wherein the catalyst is present insuch proportions that the resulting product contains about 2 to 95% byweight, preferably about 50 to 90% by weight, of the aluminosilicate inthe final composite.

The aluminosilicate-siliceous gel compositions can be prepared byseveral methods wherein the aluminosilicate is combined with silicawhile the latter is an a hydrous state such as in the form of ahydrosol, hydrogel, wet

gelatinous precipitate or a mixture thereof. Thus, silica gel formed byhydrolyzing a basic solution of alkali metal silicate with an acid suchas hydrochloric, sulfuric, etc., can be mixed directly with finelydivided aluminosilicate having a particle size less than 40 microns,preferably within the range of 2 to 7 microns. The mixing of the twocomponents can be accomplished in any desired manner, such as in a ballmill or other types of kneading mills. Similarly, the aluminosilicatemay be dispersed in a hydrosol obtained by reacting an alkali metalsilicate with an acid or an alkaline coagulant. The hydrosol is thenpermitted to set in mass to a hydrogel which is thereafter dried andbroken into pieces of desired shape, or dispersed through a nozzle intoa bath of oil or other Water-immiscible suspending medium to obtainspheroidally shaped bead particles of catalyst. The aluminosilicatesiliceous gel thus obtained is Washed free of soluble salts andthereafter dried and/or calcined as desired.

The siliceous gel matrix may also consist of a plural gel comprising apredominant amount of silica With one or more metals or oxides thereof.The preparation of plural gels is Well known and generally involveseither separate precipitation or coprecipitation techniques in which asuitable salt of the metal oxide is added to an alkali metal silicateand an acid or base as required, is added to precipitate thecorresponding oxides. The silica content of the siliceous gal matrixcontemplated herein is generally with thein range of 55 to 100 weightpercent with the metal oxide content ranging from zero to 45 percent.Minor amounts of promoters or other materials which may be present inthe composition include cerium, chromium, cobalt, tungsten, uranium,platinum, lead, zinc, calcium, magnesium, lithium, silver, nickel andtheir compounds.

The aluminosilicate catalyst may also be incorporated in an alumina gelmatrix conveniently prepared by adding ammonium hydroxide, ammoniumcarbonate, etc. to a salt of aluminum, such as aluminum chloride,aluminum sulfate, aluminum nitrate, etc., in an amount to form aluminumhydroxide, which, upon drying, is converted to alumina. Thealuminisilicate catalyst can be mixed with the dried alumina or combinedwhile the alumina is in the form of a hydrosol, hydrogcl or wetgelatinous precipitate.

While, as aforesaid, the Gattermann-Koch type reaction of the presentinvention may be carried out using a great variety of solid porouscrystalline aluminosilicate zeolites as catalytic materials, mosteffective results are obtained through the use of the acid crystallinealuminosilicates, viz., those aluminosilicates in which at least aportion of the cations are hydrogen ions. Also particularly effectiveare those aluminosilicates containing metallic cations which serveaspromoters for the synthesis, either alone or in conjunction with suchhydrogen ions. Exemplary of metallic cations which are useable for thispurpose are aluminum, cuprous, titanium, nickelous, cobaltous, tungsten,ferric, etc.

For maximum effectiveness in carrying out the process of the presentinvention, the crystalline aluminosilicate used as a catalyst for theGattermann-Koch type synthesis should have pores or channels of a sizesuch that the reactants will pass into such pores or channels and thereaction products will be removable therefrom. Quite obviously, theparticular pore size which is desirable will vary depending upon theparticular starting materials utilized and the products to be formed asa result of the synthesis. In general, however, it can be stated thatthe most desirable crystalline aluminosilicates for use in the instantprocess are those having a pore size of at least about 5 Angstrom units.If the starting materials and reaction products are highly substitutedor contain an aromatic such as benzene or naphthalene, pore sizes ofabout 6 to 13 A. are preferred.

The process of the present invention may be carried out through thesuspension of the aluminosilicate catalyst in the liquid reactant withthe introduction of the carbon monoxide and hydrogen chloride as gasestaking place in a manner more fully described in the volume of saidOrganic Reactions previously referred to and incorporated herein byreference. If desired, the reactant starting material may be dilutedwith a suitable solvent such as benzene, especially when the startingmaterial is an alkyl benzene with a labile alkyl group. Usually a ratioof benzene to starting material of between 2 and 3 to l is satisfactory.The benzene tends to inhibit the formation of dialkyl benzenes and thuslowers the amount of dialkyl benzaldehyde obtained as a by-product.

Alternately, the starting material may be sorbed in the pores of thedehydrated catalyst, and the resulting powder exposed to carbon monoxideand hydrogen chloride under reaction conditions. At the completion ofthe reaction, the product in the pores of the catalyst may be desorbed,or it may be sprung from the catalyst by contact with water or steam.Desorption may be accomplished by extraction with non-aqueous solvent,displacement by C0 etc. and the catalyst regenerated for use by simpleheating in an inert atmosphere or, if necessary, by contact at elevatedtemperature in the presence of an oxygen-containing gas to combustdeleterious residues.

Aside from the concentration of the reactant starting material in thesolvent, the most important variables in the syntheses of the presentapplication are the nature and quantity of the catalyst and the pressureand the temperature employed in the reaction.

The reactions of the present invention may be carried out either underatmospheric or higher pressures. When the aluminosilicate catalystcontains a promoter such as copper, the pressure employed may suitablybe atmospheric, though it must be pointed out that at atmosphericpressure, the reaction mixture hould be saturated with hydrogen chlorideand kept so at all times through continued addition of the gas for bestresults. At higher pressures (viz., as high as 3000 lbs. per sq. inch)in an autoclave, this is not necessary. In addition, higher pressuresalso increase the rate of absorption of the carbon monoxide andgenerally tend to increase the yield of the product. Usually,approximately twice the amount of time is required for formylation atatmospheric pressure as compared with higher pressures.

At lower pressures (i.e., atmospheric), reaction temperatures ofapproximately 3540 C. are ordinarily required, with higher pressures(i.e., about 30 to 3000 lbs. per sq. inch) permitting the process to becarried out at temperatures of approximately 25-35 C., for example.

In general, the relative quantities of materials utilized for bestresults are excess: 1 molezl molezl mole ofaluminosilicatezCO:HCl'zreactant, though it will be clear that theserelative quantities will vary depending upon the starting materialsutilized.

The following examples are illustrative of the general process of thepresent invention:

An autoclave is charged with an acidic 13Y crystalline aluminosilicatecatalyst into which has been exchanged a small amount of copper. Theautoclave is heated to 325 C. and hydrogen gas is passed through theautoclave to remove all water and to reduce the copper to the cuprousstate. After cooling to room temperature aromatic hydrocarbon is addedto cover the catalyst and dry CO and dry HCl are pressured into thereactor in equimolar quantities to a pressure of 500 p.s.i.g. For a timeCO and HCl are absorbed as noted by a gradual decrease in pressure. Thesystem is retained under pressure adding more CO and HCl as necessaryuntil no further drop in pressure occurs. The gas is then vented and thebenzaldehyde recovered from its complex with the catalyst by treatmentWith a desorbing agent which may be steam, CO or ammonia.

The yield of aldehyde from various aromatic hydrocarbons is:

The catalyst may be regenerated by heating to 325 C. temp. to remove thedesorbing agent.

In the foregoing portion of the specification, a novel process forconducting a Gattermann-Koch type synthesis by means of crystallinealuminosilicate catalysts has been set forth. It is to be understood,however, that the practice of the present invention is also applicableto isomorphs of said crystalline aluminosilicates. For example, thealuminum may be replaced by elements such as gallium and silicon byelements such as germanium.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed is:

1. In a method of carrying out a reaction in which an aromatic of theformula RH is reacted with CO and HCl to convert said aromatic to itscorresponding aldehyde, and wherein R is a carbocyclic aromatic radical,the improvement comprising carrying out said reaction with said aromaticin liquid phase in the presence of a dehydrated solid porous crystallinealuminosilicate catalyst, said crystalline aluminosilicate having poresof a size such that the reactants Will pass into such pores and thereaction products will be removable therefrom, said pores being nolarger than 13 A.

2. A method as defined in claim 1 wherein said aluminosilicate catalystis in the acid form.

3. A method as defined in claim 2 wherein said aluminosilicate catalystcontains metal cations which promote the reaction.

4. A method as defined in claim 2 wherein said metal cations areselected from the group consisting of aluminum, cuprous, titanium,nickelous, cobaltous, tungsten and ferric.

5. A method as defined in claim 1 wherein said aluminosilicate catalystcontains pores of at least about 5 A.

6. A method as defined in claim 1 wherein said aluminosilicate catalystcontains pores of about 6 to 13 A.

7. A method as defined in claim 1 wherein said aluminosilicate ismordenite in the acid form.

8. A method as defined in claim 1 wherein said re action is carried outat about 25-40 C., at a pressure from about atmospheric to about 3000psi, said aromatic, CO and HCl being present in approximatelyequimolarquantities with an excess of said catalyst being present.

9. A method of preparing benzaldehyde from benzene comprising contactingsaid benzene in liquid phase with CO and HCl under reaction conditionssuitable to convert said benzene into benzaldehyde in the presence of adehydrated solid porous crystalline aluminosilicate catalyst, saidcrystalline aluminosilicate having pores of a size such that thereactants will pass into said pores and the reaction products will beremovable therefrom.

10. A method of preparing tolualdehyde from toluene comprisingcontacting said toluene in liquid phase with CO and HCl under reactionconditions suitable to convert said toluene to tolualdehyde in thepresence of a dehydrated solid porous crystalline aluminosilicatecatalyst, said crystalline aluminosilicate having pores of a size suchthat the reactants will pass into said pores and the reaction productswill be removable therefrom.

11. A method of preparing chlorobenzaldehyde from chlorobenzenecomprising contacting said chlorobenzene in liquid phase with CO and HClunder reaction conditions suitable to convert said chlorobenzene tochlorobenzaldehyde in the presence of a dehydrated solid porouscrystalline aluminosilicate catalyst, said crystalline aluminosilicatehaving pores of a :size such that the reactants will pass into saidpores and the reaction products will be removable therefrom.

12. A method of preparing 2,4,6-trimethylbenzaldehyde from mesitylenecomprising contacting said mesitylene in liquid phase with CO and HClunder reaction conditions suitable to convert said mesitylene to2,4,6-trimethylbenzaldehyde in the presence of a dehydrated solid porouscrystalline aluminosilicate catalyst, said crystalline alumi-'nosilicate having pores of a size such that the reactants will pass intosaid pores and the reaction products will be removable therefrom.

References Cited UNITED STATES PATENTS 2/1961 Kimberlin et a1. 208465/1962 Frilette 20846 BERNARD HELFIN, Primary Examiner.

I. I. SETELIK, Assistant Examiner.

1. IN A METHOD OF CARRYING OUT A REACTION IN WHICH AN AROMATIC OF THEFORMULA RH IS REACTED WITH CO AND HCI TO CONVERT SAID AROMATIC TO ITSCORRESPONDING ALDEHYDE, AND WHEREIN R IS A CARBOCYCLIC AROMATIC RADICAL,THE IMPROVEMENT COMPRISING CARRYING OUT SAID REACTION WITH SAID AROMATICIN LIQUID PHASE IN THE PRESENCE OF A DEHYDRATED SOLID POROUS CRYSTALLINEALUMINOSILICATE CATALYST, SAID CRYSTALLINE ALUMINOSILICATE HAVING PORESOF A SIZE SUCH THAT THE REACTANTS WILL PASS INTO SUCH PORES AND THEREACION PRODUCTS WILL BE REMOVABLE THEREFROM, SAID PORES BEING ON LARGERTHAN 13 A.